There are a lot of words that will trigger the NSFW tag. P**is is one, sex is another. I had one with Dick Dastardly that got NSFW'd only to have it be removed later because I used it as his name. Unfortunately, there are many words that are NSFW'd, but there's no list of them on the site. Tampon is an NSFW word. Dick is also NSFW. Wank and Fap are. and on and on. I was really surprised this one didn't end up with the tag imgflip.com/i/1fd7ap